真空熱試驗中材料放氣的放氣量及其導(dǎo)熱問題

Material Outgassing Amount and Thermal Conduction in Vacuum Thermal Test

摘要: 材料放氣是真空熱試驗中常見的現(xiàn)象，文章分析了材料放氣的過程和機理,給出了計算放氣量的兩種方法。對于平緩的材料出氣過程，從氣體擴散的角度，利用費克第二定律求解得到了平板材料模型的氣體濃度分布，并由此計算出放氣量；對于短時間內(nèi)的劇烈放氣過程，是根據(jù)放氣后的抽氣試驗數(shù)據(jù)擬合出抽氣曲線，以此反算放氣量的大小。文章最后還分析了由于放氣而引起的低壓氣體導(dǎo)熱過程，為真空熱試驗中的相關(guān)問題提供了理論分析依據(jù)。

Abstract: Material outgassing is a common phenomenon in vacuum thermal test. In this paper, the course and mechanism of material outgassing are analyzed, and two methods of calculating outgassing amount are proposed. For a gradual outgassing course, the gas consistence distribution for a flat board model and the gas amount formula are derived according to the Second Fick Law for gas diffusion. For an acute outgassing course in a short time, a fitting curve is obtained according to the pumping data after outgassing, so the outgassing amount is obtained from the curve. Furthermore, the course of thermal conduction caused by material outgassing is analyzed as a theoretical basis to solve related problems in vacuum thermal test.